1. Field of the Invention
The present invention relates generally to vortex separators for separating floating and settling substances from centrally inflowing storm-water, in which a cylindrical guide plate is installed in a separation casing so that the space in the separation casing is partitioned into three sections, including a center space defined in the guide plate, a ring-shaped space defined between the guide plate and the inner surface of the separation casing, and a sediment storage chamber, the center space and the ring-shaped space communicating with each other at a position below the guide plate, so that storm-water spirally moves downwards in the center space and spirally moves upwards in the ring-shaped space, and, during this process, floating and settling substances and oil become separated from the storm-water and, more particularly, to a vortex separator for separating floating and settling substances from centrally inflowing storm-water, in which storm-water, which is drawn into the center space in the guide plate of the separation casing, forms a vortex in the guide plate, and, thereafter, the storm-water is moved into a ring-shaped space both by the centrifugal force of a vortex and by the inclination of a perforated inclined skirt, and, during this process, coarse and fine settling substances are moved into a sediment storage chamber through a passing hole and a guide hole of the perforated inclined skirt, thus separating settling substances, such as grit, and floating substances, such as oil and grease, from storm-water.
2. Description of the Related Art
As shown in FIG. 1, a conventional separator for separating floating and settling substances from storm-water has the following structure. A partition wall is provided in a rectangular parallelepiped body such that two sections, which are partitioned by the partition wall, communicate with each other under the partition wall. Of the two sections, one section is a separation chamber 1a, to which an inlet pipe 1 is connected such that storm-water is drawn through the inlet pipe 1, and the other section is a settlement chamber 6a, to which an outlet pipe 6 is connected such that the storm-water is discharged through the outlet pipe 6. Oil and floating substances are separated from storm-water in the separation chamber 1a, and settling substances are separated from storm-water at a lower position in the settlement chamber 6a. FIG. 1 is a plan view and a sectional view showing the conventional separator for separating floating and settling substances from storm-water.
This separator is characterized in that the size thereof can be changed depending on the flow rate of storm-water to be taken in and to increase the efficiency of removal of foreign substances. However, this separator has disadvantages in that an excessively large space for installation is required, and it is difficult to remove settled matter, which is disposed at the lower position, from the separator.
To solve these problems, a vortex separator for separating floating and settling substances from storm-water was developed. As shown in FIGS. 2 through 4, the conventional vortex separator includes a separation casing 7 and an inlet pipe 1, which is connected to the separation casing 7 so that storm-water is drawn into the separation casing 7 through the inlet pipe 1. The vortex separator further includes a dip plate 2, which is provided in the separation casing 7 at a position spaced apart from the inner surface of the separation casing 7 by a predetermined distance, and a benching skirt 3, which is provided above a sediment storage chamber (C), so that settling substances (B) are guided onto the bottom of the sediment storage chamber (C) by the benching skirt 3.
Furthermore, a center cone 4 is provided above the benching skirt 3 and is coupled to a hollow center shaft 8, which is placed in the dip plate 2. A floating substance cover 5 is provided between the dip plate 2 and the center shaft 8 to cover a ring-shaped space defined between the dip plate 2 and the center shaft 8. An outlet pipe 6, which communicates with the ring-shaped space, is connected to the dip plate 2 at an upper position. FIG. 2 is a partially broken perspective view showing the conventional vortex separator for separating floating and settling substances from storm-water. FIG. 3 is a longitudinal sectional view of the vortex separator of FIG. 2. FIG. 4 is a lateral sectional view taken along the line III-III of FIG. 3.
The operation of the conventional vortex separator having the above-mentioned construction will be explained herein below. As shown in FIG. 2, storm-water, which has been drawn into a storm-water inflow tub (A), enters the separation casing 7 through the inlet pipe 1 in a tangential direction. The storm-water thereafter rotates around the longitudinal axis of the vortex separator in the ring-shaped space, which is defined between the dip plate 2 and the inner surface of the separation casing 7. At this time, oil and floating substances rise and float on the surface of the water and are confined in the space between the dip plate 2 and the inner surface of the separation casing 7.
The storm-water continuously rotates around the longitudinal axis of the vortex separator and gradually moves towards the lower end of the dip plate 2. At this time, settling substances are moved into the sediment storage chamber (C) through an opening, which is formed at a central position through the benching skirt 3.
Thereafter, the storm-water spirally rotates around the center cone 4 slower than the speed of the outside downward flow while passing under the dip plate 2, and spirally moves upwards in the space between the dip plate 2 and the center shaft 8. Subsequently, the storm-water is discharged outside through the outlet pipe 6, which is connected at the upper position to the dip plate 2.
As such, storm-water, which has been drawn into the separation casing 7 through the inlet pipe 1, spirally moves downwards outside the dip plate 2 and spirally moves upwards in the dip plate 2 before being discharged outside the separation casing 7 through the outlet pipe 6. Because storm-water passes through such a long path, when the storm-water reaches the outlet, a lot of floating and settling material has been removed from the storm-water.
However, the conventional vortex separator has a disadvantage in that, because it is devised mostly to separate coarse settling substances from storm-water, fine settling substances cannot be reliably separated.
In other words, after storm-water is first drawn into the ring-shaped space defined outside the dip plate, coarse settling substances, which have a relatively fast settling speed, can be moved downwards in the ring-shaped space, in which the storm-water forms a relatively long and stable stream. However, the flow of storm-water changes in direction at the lower end of the dip plate and moves upwards along the center cone into the dip plate. At this time, the storm-water secondarily rotates in the dip plate. In the dip plate, because storm-water forms a relatively short and unstable stream and thus rotates around the longitudinal axis for a relatively short time before being discharged outside through the outlet pipe, some fine settling substances, which are contained in the storm-water, may be discharged along with the storm-water outside the separation casing without being deposited.
Furthermore, the conventional vortex separator requires not only a manhole for removing the settled substances through a substance removal hole but also another manhole for removing floating substances. Therefore, installation and maintenance of the vortex separator are difficult and complicated. In particular, in the case in which the vortex separator is installed in a road, the presence of two manholes may interfere with traffic.
As well, in areas where maintenance or cleaning of roads is not reliably conducted, when foreign substances, such as large stones or reinforcing bars, enter the vortex separator when it rains, it may be impossible to remove them using typical mechanical equipment. In this case, an access must be defined to allow a person to enter the vortex separator therethrough to remove them. However, because the conventional vortex separator has a structure which does not allow access by a person, the internal parts may be disassembled. As such, there is a problem in that maintenance is very difficult.